#include<bits/stdc++.h>
using namespace std;

int main(int argc, char const *argv[])
{
    int n;
    cin>>n;
    string str;
    cin>>str;
    for (int i = 0; i < str.size(); i++)
    {
        if(str[i]+ n > 'z'){
            str[i] -= 26;
        }
        str[i] += n;
    }
    cout<<str;
    return 0;

}
